The present invention relates to tube cleaning and particularly to scrubbers for cleaning the interior surfaces of tubes installed in industrial equipment such as boilers, chillers, condensers, heat exchangers, absorption machines and so forth. Such equipment ordinarily is fitted with tubes having a smooth or enhanced interior surface, and the interior surfaces are readily cleaned by means of a rotary brush. The rotary brush has a twisted steel wire spine securing bristles as illustrated in U.S. Pat. No. 5,426,807.
In operation, conventional tube cleaning equipment for tubes passes a rotary brush along the interior length of each tube to scrub soot and dirt from the tube surface. The rotary brush is accompanied by a stream of water to flush scrubbed soot and dirt from the tube.
In conventional practice rotary brushes are fitted to a rotary drive shaft by suitable screw thread means as shown for example in U.S. Pat. Nos. 2,693,611; 4,666,530; and 5,809,601.
Such screw threads are adequate for a reliable connection, for efficiently transmitting rotary motion to the brush, and are economical. However, there are operational limitations to a screw thread connection in that reverse rotation of the drive shaft tends to unthread the brush from the drive shaft so that a lock nut must be tightened in place to prevent unthreading. In addition, a change of brush requires the steps of loosening the lock nut, unscrewing the brush from the drive shaft, screwing a replacement brush onto the drive shaft, and re-securing the lock nut. In applications where brush changes are routine or frequent, the process of removing and replacing threaded connections and their lock nut becomes time consuming and undesirable in situations involving performance of a maintenance schedule on power plant equipment and other situations where xe2x80x9cdown timexe2x80x9d is costly.
The present invention provides a quick connect/disconnect rotary brush as an improvement over conventional equipment and practice.
The present invention comprises a rotary brush coupling capable of forward and reverse rotation without special arrangements, and of rapid connect/disconnect of brush to rotary drive shaft.
In a preferred form, the invention comprises a shaft coupling connected at one end to a flexible rotary drive shaft, the shaft coupling having at its other end a recess for receiving a brush coupling, and having a locking or retaining sleeve secured to the shaft coupling for movement between an open position in which a brush coupling may be fitted to or removed from the shaft coupling, and a closed position for securing a brush coupling in place for rotation and use.
The shaft coupling has a long axis and a brush coupling recess accessible in a direction normal to the axis so that the brush coupling is inserted side to side onto the shaft coupling by a sliding motion. The shaft coupling recess and the brush coupling have mating contours for ease of interfitting, smooth rotation, axial pushing and pulling as a coupling.
In preferred form, the locking sleeve is slidably mounted to the shaft coupling and comprises a cylindrical sleeve positioned and retained along the exterior of the shaft coupling body for covering and uncovering the shaft coupling recess to secure a brush coupling in place on the shaft coupling for rotation and use and to accommodate rapid brush change. The locking sleeve holds the brush coupling in place against side to side movement with respect to the shaft axis while the brush coupling contour fixes and holds axial brush position in the shaft recess under the locking sleeve for rotation in use.
A locking spring fitted to the shaft coupling urges the locking sleeve into closed position over the shaft coupling recess. In preferred form, both the locking sleeve and locking spring are positioned and retained on the exterior surface of the shaft coupling. In use, the locking sleeve slides axially of the shaft coupling against spring force, and after a change of brush couplings, the sleeve is released and springs back to locked position.
In another preferred form of the invention, the locking sleeve and the locking spring are mounted on the shaft coupling in nested relation to each other with the locking sleeve enclosing the spring on the shaft coupling.
An aspect of the invention is to provide a brush coupling adapter for quick connection to a shaft coupling as in the case of the preferred embodiment, and for receiving a brush member by means of a standard threaded connection.
The quick disconnect tube cleaning brush is of robust, economic construction facilitating reliable and efficient rotary connection between drive shaft and rotary brush, while permitting immediate brush removal and replacement during tube cleaning operations.
Specific examples are included in the following description for purposes of clarity, but various details can be changed within the scope of the present invention.
An object of the invention is to provide a new and improved coupling for brushes.
Another object of the invention is to a quick disconnect brush coupling for rapid change of brushes on a drive shaft.
Another object of the invention is to provide a brush coupling with a sliding side-to-side connection of brush to drive shaft with locking sleeve to secure brush in position for rotary and/or axial use.
Another object of the invention is to provide a quick disconnect rotary brush coupling with a shaft coupling recess accessible from one side of the shaft coupling so as to retain structural integrity of the brush coupling in view of operational stresses encountered in practice.
Another object of the invention is to provide a quick disconnect brush coupling which is robust for reliable and efficient transmission of motion to brush, simple to interchange by operator at tube cleaning site, and economical.
Another object of the invention is to provide a brush coupling adapter for connection to a shaft coupling in accordance with the invention, and for use with a conventional tube cleaning brush.
Another object of the invention is to provide a quick disconnect brush coupling with locking sleeve and locking spring components in nested relation to each other on the shaft coupling with the sleeve enclosing the spring.
Other and further objects of the invention will become apparent with an understanding of the following detailed description of the invention or upon employment of the invention in practice.